8IWA

Crystal structure of Q9PR55 at pH 6.5

8IWA の概要

• エントリーDOI: 10.2210/pdb8iwa/pdb
• 分子名称: Uncharacterized protein UU089.1, SULFATE ION (3 entities in total)
• 機能のキーワード: knotted protein, structural protein
• 由来する生物種: Ureaplasma parvum serovar 3 str. ATCC 700970
• タンパク質・核酸の鎖数: 8
• 化学式量合計: 84216.90

構造登録者

Hsu, M.F.,Ko, T.P.,Huang, K.F.,Chen, Y.R.,Huang, J.S.,Hsu, S.T.D. (登録日: 2023-03-29, 公開日: 2024-02-07)

主引用文献

Hsu, M.F.,Sriramoju, M.K.,Lai, C.H.,Chen, Y.R.,Huang, J.S.,Ko, T.P.,Huang, K.F.,Hsu, S.D.
Structure, dynamics, and stability of the smallest and most complex 7 1 protein knot.
J.Biol.Chem., 300:105553-105553, 2023

PubMed Abstract: Proteins can spontaneously tie a variety of intricate topological knots through twisting and threading of the polypeptide chains. Recently developed artificial intelligence algorithms have predicted several new classes of topological knotted proteins, but the predictions remain to be authenticated experimentally. Here, we showed by X-ray crystallography and solution-state NMR spectroscopy that Q9PR55, an 89-residue protein from Ureaplasma urealyticum, possesses a novel 7 knotted topology that is accurately predicted by AlphaFold 2, except for the flexible N terminus. Q9PR55 is monomeric in solution, making it the smallest and most complex knotted protein known to date. In addition to its exceptional chemical stability against urea-induced unfolding, Q9PR55 is remarkably robust to resist the mechanical unfolding-coupled proteolysis by a bacterial proteasome, ClpXP. Our results suggest that the mechanical resistance against pulling-induced unfolding is determined by the complexity of the knotted topology rather than the size of the molecule.

PubMed: 38072060
DOI: 10.1016/j.jbc.2023.105553

実験手法

X-RAY DIFFRACTION (2.51 Å)